10 posts.
L2s differ on two independent axes: how they prove state (validity/ZK proofs vs fraud proofs) and where they put data availability (on Ethereum vs off-chain). Those two choices give you rollups, validiums, and optimiums — with real differences in cost, security, and worst-case fund recovery. Here's the taxonomy, plainly, and why it matters for developers.
Read →Account abstraction lets a smart contract — not a private key — decide what makes a transaction valid, enabling gasless UX, social recovery, session keys, and batching. This explainer covers the EOA-vs-contract-account split, how ERC-4337 adds AA on top of Ethereum with UserOperations and bundlers, and how chains like zkSync and Starknet make accounts contracts natively.
Read →On Ethereum, 'the RPC' is one JSON-RPC endpoint. On Cosmos chains, 'RPC' can mean three different interfaces — Tendermint/CometBFT RPC, REST (LCD), and gRPC — each on its own port, each for a different job. Here's what each one does, when to use it, and the mental shift from calling contracts to querying modules.
Read →MEV — maximal extractable value — is why your swap sometimes executes at a worse price than you saw, and why validators reorder transactions for profit. A plain-English tour of front-running, sandwiches, and back-running, how the public mempool enables it, and what you can actually do about it.
Read →You send a transaction and it just says 'pending' — where does it actually go? A plain-English tour of the mempool: how transactions wait, why fees and nonces decide their fate, how to watch them, and how to unstick one.
Read →Your L2 transaction confirms in under a second — but that's not the same as final. Here's the difference between a sequencer's soft confirmation and true L1-settled finality, why optimistic and ZK rollups answer it differently, and how to check finality from RPC.
Read →Most developers either overpay for an archive node they don't need or hit a wall on a full node that can't answer their query. The difference comes down to one thing — historical state — and here's the simple test for which one your app actually requires.
Read →Every RPC provider limits you, but they don't agree on what a limit even is. One caps requests per second, another meters compute units, a third deducts API credits. Here's how the three models work, why the same workload costs differently on each, and how to estimate your own number.
Read →Every blockchain tutorial says 'connect to an RPC endpoint' and then moves on. Here's what one actually is, what the URL means, how a request works, and when you need a provider — in five minutes.
Read →What an Ethereum archive node actually costs today — hardware, sync time, bandwidth, hosted options — and the threshold where renting one beats running it yourself.
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